The Collision Prevention Strategies (CPS) program is intended to address the problem of right angle collisions at signalized intersections by focusing on red light violations as a surrogate measure. Crash statistics usually take months or years to develop significant numbers, while red light violation statistics can be captured in a matter of days or weeks making this surrogate measure an attractive new tool. The intent of this project was to develop and apply a process of monitoring Red Light Running Violation rates as a performance measure. This tool can be utilized to diagnose the root cause of violation rates and to evaluate the results after countermeasures have been applied.

The foundation of this Mn/DOT program stems from a multi-agency partnership in Minnesota known as Toward Zero Deaths, which established a goal of zero deaths on the State’s roadways. To achieve this goal, it is helpful to divide all crashes into categories, with right angle collisions at signalized intersections being one of the most critical. The focus on right angle collisions is important because they tend to be the most damaging in terms of fatalities, personal injuries and property damage.

The first project, CPS I, successfully explored the possibility of measuring red light violations using conventional vehicle detection equipment. CPS II took this to the next level and refined the measurement tools and processes in a real world environment.

The plan called for the implementation of engineering countermeasures at one intersection (Snelling Avenue at St. Anthony Avenue), and enforcement countermeasures at a second intersection (Arcade Street at Minnehaha Avenue). Both intersections were instrumented with sonic vehicle detection equipment, and a baseline violation rate was established for each designated approach. Clearance Interval signal timing changes were implemented at the first intersection and targeted enforcement was conducted at the second.